How to identify computer chips or integrated circuits on circuit boards
Chip part numbers do not always follow any pattern, manufacturers tend to form a naming style but this is not always true. Often it is difficult to describe the patterns they are so random, but as you become familiar with IC part #, You begin to see the patterns more easily. This page lists some patterns and techniques for deciphering the part numbers; however, there are no rules, so these hints will not work in all cases. Before looking at the part number There is a lot you can learn from a chip before event looking at the part number. Manufacturer Indentification Manufacturers tend to focus on certain sectors of the IC business, and avoid other sectors. So identifying the manufacturer can bring you a great deal closer to its function. Here is a list of hundreds of manufacturers and what they specialize in: http://www.elnec.com/iclogos_n.php To identify the manufacturer See: Guide to IC manufacturer logos If there is no logo, the manufacturer can often be found in the part number itself. See the Manufacturer Prefixes Section Chip Package Indentification The chip package can also give you hits as to its function. *See: Guide to IC packages ;Chip Package styles before 1990 *CPUs & FPUs: mostly CDIPs, higher end CPUs used PGAs. **Usually removable *MCUs:CDIP *UV EPROMs: Always CerDIP with a sticker covering a window to the die. *Basic Logic: Usually Ceramic SDIPs *Resistor Chains: yellow or orange(not black) SIPs, or SDIPs ;Chips after 1995 *CPUs & FPUs: PGAs *MCUs: PDIP, *CPU & MCUs support chips:PDIP, SOIC *EEPROMs: PDIP *RAM: SOIC *Basic Logic: plastic SIPs, SOIC ;Chips after 2000 *Flash Memory: TTSOP, BGA Identify by Application If you know the function of the board your chip is on then you know what basic functions chips on the board would have to perform. * A computer motherboard would generally have a CPU, maybe a FPU, a bios chip, cache memory, and a few bus controllers. Narrowing down the different functions of each chip on the board can help you guess your chips function. Identifying and deciphering the part number Decyphering a chip's part number is a very ambitious process and most of the time, typing the whole part number in a search engine gets you nowhere. General Format In general computer chips or integrated circuits follow the following format *Line 1: Manufacturer's Name *Line 2: Part number *Line 3: date code, and other coded information *:Less often lines 2 and 3 are reversed Part number generally follows the following formats *characters for manufacturergeneric part #chars for package, revision, etc *:for example Am2901ADC, for AMD2901A,D=ceramic,C=? *:or SY6502, for Synertek6502 *Another common part number style is typepart#speed,rev.,... *:for example A80486DX-16, for pin grid array80486, or more commonly called [[486]]DX, speed 16MHz *:or P8080A, for [[dip] package]8080A Manufacturer Prefixes Below is a table of common manufacturers part number prefixes, this are not always true, but most of the time they are. Common IC Families The quickest way to identify the chip is to identify that it is a member of a IC family. By identifying the family you find the function without worry about prefixes and suffixes *80x86 **Examples: 8086, 80186,80286,80386,80486 **Full part #: D8086, A80386DX-16 *80xx based MCUs **Examples: 8031, 8051, 8049, 8048, 80151, 80251 **Full part #: N80C31BH, S-80C31, P8048H *7400 TTL Logic Series **Follows the format, alpha char74typedigits for the distinct functionalpha char ***What to look for is 74typedigits **there are many types of chips for each function, that describe speed, power, technology, voltage,.... ***Some of these are:nothing,LS,AS,ALS,F,C,HC,AC,AHC,.. ***See: wikipedia:7400_series **The function number, called the part pumber with the 74 in front, goes from 00 to 882, There are a few with 4 digits but they are uncommon *** for full list with functions See: wikipedia:List_of_7400_series_integrated_circuits **Examples:74LS02, 74HC14 **Full Part #'s: CD74AC04E, SN74AUC14RGYR * 4000 CMOS Logic ** 4000 to 4585 *MC68xx MC68xxx ** Motorola 6800 and 68000 CPUs and there support chips **Example: MC68HC12 * PAL Programmable array logic ** Not really a family, but usually have PAL in the name or one the chip Seaching the part number Usually searching a part number results in hundreds of useless pages with large lists of part numbers, and no information. IC datasheet archives :These are some reputable datasheet searches, there are allot of fake commercial ones. *http://www.datasheetcatalog.com/ *http://www.alldatasheet.com/ *http://www.datasheetarchive.com/ This search box will search Google while filtering out most of the useless pages: -site:www.electrospec.com -site:www.cmbcomponents.com -site:www.usbid.com -site:www.hkinventory.com -site:klava.ru -site:www.semirim.com -site:www.freetradezone.com -site:www.isocomponents.com -site:www.netcomponents.com -site:www.1sourcecomponents.com -site:www.icxinyi.com -site:nowel.ru -site:www.dzsc.com.cn -site:www.icpart.com -site:www.class-ic.com -site:www.hqew.com -site:www.icminer.com"> or click the lick below and add you part number to the begining of the search box *Google IC search with filtered results Common Families *Wikipedia Lists **List of 7400 series integrated circuits **List of AMD Am2900 and Am29000 families Specific Companies Nomenclature * http://www.cpu-world.com/info/id/index.html: ***Very Useful*** - has full identification part # codes for AMD Athlon 64,Opteron, Athlon, Athlon XP, Athlon MP, Duron, AMD K6, K6-2, K6-III, AMD Sempron, AMD x86 (8086 - K5), AMI, AT&T, CMD, CSG, Cypress Semiconductor, Cyrix, Fairchild, Harris, Hitachi, Hughes, IBM, IDT, Intel 80486, Intel Pentium, Intel Pentium II, Intel Pentium III, Intersil, Microchip, Mitsubishi, Mostek, Motorola, NEC, National Semiconductor, OKI, Philips, RCA, Rise Technology, Rockwell, SGS, ST, Siemens, Signetics, Sony, Synertek, Texas Instruments, Toshiba, Transmeta, UMC, WDC, Zilog * NAMCO http://www.multigame.com/NAMCO.html * NEC http://www.necel.com/en/faq/f_name.html *ATARI http://www.aarongiles.com/atariic.html * Allegro MicroSystems http://www.allegromicro.com/techpub2/partno.pdf * Steward http://www.steward.com/pdfs/emi/circuitboards/Nomenclature.pdf * Wang IC http://www.oldcalculatormuseum.com/t-wangic.html * International Rectifier http://www.irf.com/product-info/hi-rel/nomenclature.html =Example of Identifying chips in a circuit boards= #Board's function Identification 1: Board's function Identification Assuming we had no idea where the board came from this board's function is easy to identify. W could look up the part # on google, but often that information is long lost so be have to use other methods. i From a glance at the board there are several identifiable markings. *A: Large chip in a pin grid array package *: generally large PGAs are CPUs, but we could also search google for Intel i960 and find that it is a CPU for servers or high end workstations. *B: Simm chip sockets *: These are obviosly for RAM *C: standard computer plugs *: clearly identifying it as a computer *D: floppy drive *: and computer often have floppy drive ports From these features we know that it is a server or high end workstation motherboard. Chip functions Guesses in chips functions with out looking up the part number I have divided the board up into three section to make in easier to describe. Section 1 *A: the circuit in the is obviously a DC-DC converter, because it is a compact, and separate circuit consistion of capacitors inductors/transformers, largetransistors and diodes. It is also likely that the chips around it are drivers for the transistor, compensators or otherwise involved in the converter. :a DC-DC converter is usually near the power input or the CPU, but it is not on this board. *B: These chips are some sort of resistor arrays. Colored DIPs, SIPs, or SOICs are always resistor arrays. They are often near output ports or LED arrays. *C: These IC are most likely drivers, buffers, for the output ports to increase signal integrity. This is shown by their closeness to the output ports. *D: The Bt chip says RAMDAC. this is often involved in video monitors. Bt makes RAMDAC video processors, and the closeness to the VGA port further conferns this. *E: This chip is ambiguous, and will most likely have to be looked up. Search on a search engine for HP and one of the lines of Alphanumerics. This chip is even hard to decipher which line is the part number, but one will be. However data about this chip may be proprietary or lost in time. *F: These chips could be a number of things. Since they are all the same and to small to be memory they are probably drivers or buffers. SOICs often have these simply functions and if they are these functions then the part numbers will usually be easy for find their datasheets. G: These chips functions are hard to say. they may be signal drivers for the ethernet plugs. But their functions will probably have to be looked up. H: This chip has a frequency on it, so it is an oscillator, clock, crystal or resonator. Any of these functions are used to make a clock. Section 2 =Ram= *http://www.ddrmemoryupgrades.com/howto_identify_size_of_ram.html =See Also= * Guide to IC packages From HowTo Wiki, a Wikia wiki. Category:Howto